1. Field of the Invention
The present invention relates to a compressor used for a vehicular climate control system or the like.
2. Description of the Related Art
Swash plate type compressors employed for vehicular climate control systems have been known. The swash plate type compressor disclosed, for example, in Japanese Patent Application Laid-open No. 59-113278 filed Jun. 29, 1984 in the name of Nippon Denso Co. Ltd. and EPA Publication No. 0 595 313A1 filed Oct. 28, 1994 in the name of Sanden Corporation, each have cylindrical compression chambers in a cylinder block assembly. Fluids to be compressed are compressed by pistons serving as fluid compressing members provided in each of the compression chambers.
Swash plate type compressors are also equipped with front and rear housings serving as covering members for covering the compression chambers of the cylinder block assembly. Valve plates which have inlet ports through which fluids to be compressed are drawn into the compression chambers from the suction chambers formed in the housings, and discharge ports through which the fluids, which have been compressed by the pistons, are discharged into discharge chambers formed in the housings, are respectively provided between the housings and the cylinder block assembly.
The foregoing swash plate type compressors are further equipped with metallic discharge valve forming plates respectively provided between the valve plates and the housings. Plate-shaped metal gaskets respectively disposed between the discharge valve forming plates and the housings provide airtight sealing between the discharge valve forming plates and the housings.
Discharge reed valves of such compressors are formed by the above mentioned discharge valve forming plates; hence, if the compressed fluids discharged through the discharge ports have a high pressure, the discharge reed valves may be deformed beyond the elastic limit of the discharge valve forming plates. To prevent deformation or the like of the discharge reed valves, conventional compressors have retainers provided on the side opposite the respective discharge ports with the discharge reed valves placed between them so as to restrict the magnitude of opening of the discharge reed valves within the elasticity range of the discharge valve forming plates.
In such compressors, however, the retainers for restricting the magnitude of opening of the discharge reed valves are formed integrally with the foregoing metal gaskets which are extremely thin. For this reason, as the compressed fluids discharged through the discharge ports repeatedly hit the retainers, the retainers are deformed away from the discharge reed valves, leading to the likelihood that the magnitude of opening of the discharge reed valves will no longer be restricted to the elasticity range of the discharge valve forming plates.
As a conceivable measure for preventing the retainers from being deformed, the metal gaskets placed between the discharge valve forming plates and the housings can be made thicker. Making the metal gaskets thicker, however, poses the problem of impairing sealing performance of the metal gaskets.
The present invention has been accomplished with the view toward solving the problem described above. It is an object of the invention to provide a compressor which is able to prevent a retainer from being deformed without damaging the sealing performance of a metal gasket provided between a covering member which covers a compression chamber of a cylinder block assembly and a discharge valve forming plate.
To this end, according to the present invention, there is provided a compressor equipped with: a cylinder block assembly having at least one compression chamber; a fluid compressing member housed in each compression chamber for compressing a fluid; at least one covering member connected to one end of the cylinder block assembly to cover the compression chamber and defining a discharge chamber therein for receiving a fluid compressed by the fluid compressing member; at least one valve plate provided between the covering member and the cylinder block assembly and having at least one discharge port through which the fluid compressed by the fluid compressing member is discharged into the, discharge chamber; at least one metal discharge valve forming plate provided between the valve plate and the covering member to form at least one discharge reed valve for opening and closing the discharge port; at least one plate-shaped metal gasket provided between the discharge valve forming plate and the covering member; and at least one retainer formed so as to have a gently rising portion in the metal gasket to restrict the magnitude of opening of the discharge reed valve; wherein the covering member has a restricting section formed at a distal end of a cylindrical wall protruding from an inner surface thereof at a position corresponding to the proximal portion of the rising portion, and which restricts the deformation of the proximal portion of the rising portion of the retainer.
With this arrangement, the restricting section provided on the covering member prevents the rising portion of the retainer from being deformed by the compressed fluid discharged through the discharge port when the discharge valve is actuated. This eliminates the need to increase the thickness of the metal gasket provided between the discharge valve forming plate and the covering member, so that deformation of the retainer can be prevented without sacrificing the sealing performance of the metal gasket which seals the compression chamber of the cylinder block assembly.
In a preferred form of the present invention, the foregoing restricting section has an end surface of the cylindrical wall formed to approximately match the shape of the top surface of the proximal portion of the rising portion in a section taken in the direction of the thickness of the metal gasket. With this arrangement, the top surface of the proximal portion of the rising portion of the retainer does not come into local contact with the restricting section when the retainer is restricted at the time of discharge, thus minimizing the chance for wear.
In another preferred form of the present invention, the end surface of the cylindrical wall in the restricting section is formed to have an arc shape almost identical to that of the top surface of the proximal portion of the rising portion. With this arrangement, the surface of the restricting section comes into even contact with the top surface of the proximal portion of the rising portion of the the retainer when the retainer is lifted at the time of discharge. This minimizes the chance for wear.
In a further preferred form of the present invention, the restricting section comprises an intermediate surface connecting the outer periphery surface and the end surface of the cylindrical wall, which is formed to have an arc shape in a section taken in the direction of the thickness of the metal gasket. With this arrangement, sealant for the metal gasket will not protrude into the discharge chamber through a gap formed between the top surface of the rising portion of the retainer and the surface of the restricting section when the proximal portion of the rising portion of the retainer is pushed by the restricting section. This prevents the retainer from being deformed due to deterioration of the metal gasket.